Claude Code 2.1.178: Parameterized Permission Rules and Nested Skills
Anthropic
Claude Code version 2.1.178 (June 15, 2026) adds Tool(param:value) syntax for permission rules, enabling fine-grained matching on tool input parameters with wildcard support — for example, Agent(model:opus) can block Opus subagents specifically. Nested .claude/skills directories now load automatically when working in those directories, with name-clash resolution via <dir>:<name> namespacing. Auto mode now runs a classifier check before spawning subagents to prevent blocked actions from being delegated. Multiple bug fixes address OOM crashes from stale file-descriptor env vars, OAuth account mismatches in Chrome, subagent transcript handling, compaction fallback model, and VSCode CJK IME dismissal.
Why it matters
The parameterized permission syntax is a significant ergonomics improvement for teams enforcing model-tier policies in agentic pipelines — it moves cost and safety controls from blunt model blocks to surgical parameter-level rules. Nested skill inheritance with closest-directory-wins makes multi-project monorepos viable without permission prompt friction.
Importance: 3/5
Notable Claude Code release with a meaningful new permission model for agentic pipelines; nested skills address a long-standing monorepo limitation.